| A pair of non-circular gear rack pairs are generally used between the steering shaft and the rocker shaft of the automobile steering gear to achieve non-uniform speed transmission in the steering process.At present,the enterprise lacks in-depth theoretical analysis of the meshing performance of the non-circular gear pair.Most of them use experience and trial and error methods to make the product development cycle long and inefficient.To this end,based on the meshing principle of the non-circular toothed rack pair,the geometric motion relationship is studied,and the influence of the meshing performance parameters such as coincidence degree,meshing clearance and tooth root strength on the variable speed transmission is analyzed,and the parameterized design software is developed based on MATLAB,To provide theoretical and technical support for the design and manufacture of non-circular gears for automobile steering gears.The main research contents include:Study the method of envelop method to solve the non-circular tooth profile.According to the principle of envelope,combined with the spatial geometric relationship,the envelope method is derived to solve the tooth profile equation.Compare the tooth profile it solves with the tooth profile normal equation derived from the meshing principle and the spatial geometric relationship to verify the correctness and accuracy of the method and discuss the characteristics of the two tooth profile solving methods.The research index of non-circular gear fan meshing performance is proposed.Starting from the failure mode of the gear transmission,it is determined that the degree of coincidence,backlash,common normal length,and root strength are the performance indicators that need to be considered in the gear design stage,and the calculation formula of this index is derived.The influence of cutter radius on the tooth root strength was studied,and the variation rule of cutter radius and tooth root strength was obtained,and the optimal value range of cutter radius was determined.Development of two-dimensional parametric design software for non-circular gear fan of automobile rocker shaft.Based on the GUI(Graphical User Interface)function of MATLAB,the geometric principle of the non-circular gear rack and pinion pair is applied to realize the input of geometric design parameters of the non-circular gear pair,calculation of the coordinates of the tooth profile of the large and small ends,graphics and simulation,backlash,common normal length and coincidence calculation And other main functions,help enterprises to build a two-dimensional parametric design platform for non-circular gears,which greatly facilitates corporate designers.Verify the correctness of the calculation of the tooth profile coordinates of the 2D parametric design software.For the non-circular gear fan actually processed by the gear shaping machine,the developed non-circular gear fan two-dimensional parametric design software was used to simulate the tooth profile,and the Klinberg P26 gear testing center was used for experimental verification,and the display errors were within a reasonable range.The correctness of the tooth profile coordinates calculated by the parameterized software is verified. |
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